M.R. Danter

Prospective Randomized Evaluation of Implantable Cardioverter‐Defibrillator Programming in Patients With a Left Ventricular Assist Device

Background Ventricular arrhythmias are common in patients with left ventricular assist devices (LVADs) but are often hemodynamically tolerated. Optimal implantable cardioverter defibrillator (ICD) tachy‐programming strategies in patients with LVAD have not been determined. We sought to determine if an ultra‐conservative ICD programming strategy in patients with LVAD affects ICD shocks. Methods and Results Adult patients with an existing ICD undergoing continuous flow LVAD implantation were randomized to standard ICD programming by their treating physician or an ultra‐conservative ICD programming strategy utilizing maximal allowable intervals to detection in the ventricular fibrillation and ventricular tachycardia zones with use of ATP. Patients with cardiac resynchronization therapy (CRT) devices were also randomized to CRT ON or OFF. Patients were followed a minimum of 6 months. The primary outcome was time to first ICD shock. Among the 83 patients studied, we found no statistically significant difference in time to first ICD shock or total ICD shocks between groups. In the ultra‐conservative group 16% of patients experienced at least one shock compared with 21% in the control group (P=0.66). There was no difference in mortality, arrhythmic hospitalization, or hospitalization for heart failure. In the 41 patients with CRT ICDs fewer shocks were observed with CRT‐ON but this was not statistically significant: 10% of patients with CRT‐ON (n=21) versus 38% with CRT‐OFF (n=20) received shocks (P=0.08). Conclusions An ultra‐conservative programming strategy did not reduce ICD shocks. Programming restrictions on ventricular tachycardia and ventricular fibrillation zone therapy should be reconsidered for the LVAD population. The role of CRT in patients with LVAD warrants further investigation. Clinical Trial Registration URL: https://www.clinicaltrials.gov. Unique identifier: NCT01977703.

Surgical considerations and challenges for bilateral continuous-flow durable device implantation

The concept of biventricular support with durable centrifugal pumps is evolving, and the surgical strategy and best practice guidelines for implantation of right-sided devices are still unknown. We present optimal strategy for bilateral HeartWare continuous-flow ventricular assist device (HVAD) implantation in a series of four patients. Patients were implanted with the HVAD pumps simultaneously or sequentially. This report offers a perspective on surgical considerations such as right ventricular positioning, implications related to potential risks of obstruction from the tricuspid apparatus, the role if any of downsizing the outflow anastomosis, and considerations for speed adjustments. In this series, one patient died on support and three patients experienced pump thrombosis requiring device revision. All other patients survived until orthotopic heart transplantation, although one of these patients died from perioperative complications, 2 days posttransplantation. Surgical management of patients with medically refractory biventricular heart failure remains challenging and associated with a high incidence of pump thrombosis. Best practice guidelines from experts’ consensus are still needed to address this challenging population.

Driveline Infection Risk with Utilization of a Temporary External Anchoring Suture After Implantation of a Left Ventricular Assist Device.

Driveline infections (DLI) are a cause of morbidity after continuous-flow left ventricular assist device (CF-LVAD) implantation. Because driveline trauma contributes to DLI, we assessed whether intraoperative placement of a temporary external anchoring suture (EAS) influenced DLI rate. We analyzed 161 consecutive patients with CF-LVAD (HMII 82; HW 79) implantation. Two groups were defined: placement of EAS (n = 85) or No EAS (n = 76). For NO EAS patients, the driveline was permanently anchored internally to the rectus fascia. Cox proportional analysis was performed to assess the effect of EAS on time to first confirmed DLI. Baseline characteristics were comparable between groups (all p = 0.3). Mean follow-up time was 0.93 years. A total of 18 (11.1%) patients developed confirmed culture positive DLI, with “first infection” rate of 0.13 events/year. Mean time to confirmed DLI was 0.69 years. Driveline infection was less likely (hazard ratio [HR] = 0.28, 0.95 confidence interval [CI] = 0.06–1.25, p = 0.056) to occur in NO EAS (2/18) then in EAS (16/18). Confirmed DLI was comparable between device types (p = 0.3). Multivariable regression adjusted for age, BMI, blood product use, device type, and diabetes showed equivocal effect of EAS (HR = 0.33, 0.95 CI = 0.07–1.54, p = 0.12). Patients with a temporary EAS may have an increased risk of confirmed DLI after device implantation.

An Extreme Example of Subclavian Crush

The patient presented in 2008 for follow-up of her implantable cardioverter-defibrillator, which had reached its elective replacement indicator. The ventricular lead was a Medtronic 6949 lead (Minneapolis, Minnesota), which was electively replaced with the current Medtronic 6947. There was

Can an Alternative Outflow Strategy be Utilized for High-Risk Bridged Patients with Previous Cardiac Surgery?

The HeartWare ventricular assist device (HVAD) is an implantable continuous-flow centrifugal pump that has allowed the development of sternal-sparing techniques, with the use of alternative outflow strategies. We compared early outcomes for patients bridged with the conventional versus alternative outflow graft strategy. From January 2013 to October 2014, 89 patients with HVAD implantation were identified. Survival was analyzed with Kaplan–Meier methods, and a log-rank test was used to compare outcomes between groups. Thirty patients (34%) had ≥1 previous sternotomy before HVAD implantation. Eight patients (27%) were approached using an alternative outflow graft technique with outflow graft connection to the descending aorta (n = 4, 50%) or left subclavian artery (n = 4, 50%), whereas 22 (73%) were implanted via a conventional sternotomy approach with the outflow graft to the ascending aorta. Preoperative characteristics (age, Interagency Registry for Mechanically Assisted Circulatory Support [INTERMACS], and Lietz-Miller score) were comparable between groups (all p > 0.05). Median follow-up was 4.7 (2.8–9.3) months of support. Outcomes were comparable between conventional and alternative outflow groups; survival at 6 months was 74% for the conventional group and 83% in the alternative outflow group. An alternative outflow graft strategy can be utilized to support bridged patients with a history of prior sternotomy.